DAYTON, Ohio -- Police in Dayton search along the banks of the Great Miami River for two men that robbed a hotel.The hotel robbery happened about 3:30 a.m. at the Courtyard by Marriott on Edwin C. Moses Boulevard near Interstate 75.Officers said two white males walked into the lobby and one of them pulled out a black, semi-automatic handgun and put it up to the clerk's head.The robbers demanded cash, and police said the clerk did the smart thing and did what he was told.Police Sgt. James Mullins said the two men were wearing partial masks that, "Covered the bottom part of their faces, not the whole faces, the clerk could tell they were white males."Mullins said once the two men got the money, they forced the clerk to walk outside and to a darkened path that runs behind the hotel, along the banks of the Great Miami River. The men then told the clerk to walk in one direction while they took off on foot, heading in the opposite direction.Mullins said the clerk kept his cool and waited a reasonable amount of time, then, "I think he knew the other guys were gone, they were out of his sight, so he came back and called us."Officers from the Dayton Police Department and the University of Dayton quickly arrived and began checking the riverbanks on both sides of the freeway. The men were not found.Police brought in a K-9 to help track the men down, but the dog lost the scent in a hazardous area near the freeway.Mullins said the hotel did have cameras and, "The video will certainly help us, also we had an evidence crew come in to try to lift fingerprints from the lobby."Police said it will be later in the day Tuesday before they will know if the surveillance system recorded pictures that can help identify the two robbers.